Supplemented Hypokinetic Subjects Groups Research Articles

Inadequacy of calcium supplements to normalize muscle calcium deficiency in healthy subjects during prolonged hypokinesia

Objective We investigated the effect of hypokinesia (diminished movement) on muscle calcium (Ca 2+) content with and without Ca 2+ supplementation and Ca 2+ loss with different muscle Ca 2+ deficiency; muscle Ca 2+ content, plasma Ca 2+ level, and Ca 2+ loss were measured. Methods Studies were performed in 40 physically healthy male volunteers during a pre-experimental period of 30 d and an experimental period of 364 d. Subjects in equal numbers were assigned to one of four groups: unsupplemented active control subjects (UACSs), unsupplemented hypokinetic subjects (UHKSs), supplemented active control subjects (SACSs), and supplemented hypokinetic subjects (SHKSs). A daily supplementation of 0.7 mmol of calcium lactate per kilogram of body weight was given to SACSs and SHKSs. Results Muscle Ca 2+ content decreased, and plasma Ca 2+ concentration and Ca 2+ loss in urine and feces increased ( P < 0.05) in the SHKS and UHKS groups compared with their pre-experimental values and the values in their respective active control groups (SACS and UACS). However, muscle Ca 2+ content decreased more, and plasma Ca 2+ concentration and Ca 2+ loss increased more ( P < 0.05) in the SHKS group than in the UHKS group. Conclusion Muscle Ca 2+ deficiency is more evident when Ca 2+ intake is higher and Ca 2+ loss is more exacerbated with higher than with lower muscle Ca 2+ deficiency, indicating that muscle Ca 2+ deficiency during prolonged hypokinesia is due to an inability of the body to use Ca 2+ but not to a Ca 2+ shortage in the diet.

Measurements in Potassium-Supplemented Athletes During and After Hypokinetic and Ambulatory Conditions

Hypokinesia (diminished movement) induces significant potassium (K) changes; however, little is known about K deposition and deficiency during hypokinesia (HK). Using K supplements during and after HK, the aim was to establish body K deposition and K deficiency during HK. Studies were done during the pre-HK period of 30 d, HK period of 364 d, and post-HK period of 30 d. Forty male trained athletes aged 24.9 +/- 8.0 y were chosen as subjects. They were equally divided into four groups: unsupplemented active control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented active control subjects (SACS), and supplemented hypokinetic subjects (SHKS). Hypokinetic subjects were limited to an average walking distance of 0.7 km/d. Control subjects ran an average distance of 11.6 km/d. The SHKS and SACS groups took 95.0 mg elemental K/kg body weight daily. Fecal K excretion, urinary sodium (Na) and K excretion, plasma K and Na levels, plasma renin activity (PRA), plasma aldosterone (PA), food and fluid intake, and physical characteristics were measured. During HK, fecal K loss, urinary K and Na loss, and plasma K, Na, PRA, and PA levels increased significantly (p < or = 0.05), whereas during the initial days of post-HK, the levels of the measured parameters decreased significantly (p < or = 0.05) in the SHKS and UHKS groups as compared with the SACS and UACS groups, respectively. During HK, body weight, body fat, peak oxygen uptake, food and fluid intake decreased significantly (p < or = 0.05), whereas during the initial days of post-HK period remained significantly (p < or = 0.05) depressed and fluid intake increased in SHKS and UHKS groups when compared with the SACS and UACS groups, respectively. However, during HK and post-HK plasma, urinary, and fecal K changed significantly (p < or = 0.05) more in the SHKS group than in the UHKS group. The deposition of K was significantly (p < or = 0.05) lower and K deficiency much higher in the SHKS group than in the UHKS group. Fecal K loss, urinary K and Na loss, plasma K, Na, PRA, and PA levels, body weight, body fat, peak oxygen uptake, and food and fluid intake did not change significantly in the SACS and UACS when compared with their baseline control values. It was shown that plasma K concentration and urinary and fecal K excretion increased during HK and decreased significantly (p < or = 0.05) during post-HK. Oral K supplements did not influence plasma or fecal and urinary K either during HK or post-HK. It was concluded that the low plasma K level and fecal and urinary K loss during post-HK may indicate the presence of K deficiency, and increased K in plasma, urine, and feces during HK and in the presence of K deficiency may suggest the body's inability to retain K during HK.

Effect of fluid and salt supplementation on body hydration of athletes during prolonged hypokinesia

Body hydration decreases significantly during hypokinesia (HK) (diminished movement), but little is known about the effect of fluid and salt supplements (FSS) on body hydration during HK. The aim of this study was to measure the effect of FSS on body hydration during HK. Studies were done during 30 days pre HK period and 364 days HK period. Thirty male athletes aged 24.5±6.6 yr were chosen as subjects. They were equally divided into three groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic subjects (UHKS) and supplemented hypokinetic subjects (SHKS). Hypokinetic subjects were limited to an average walking distance of 0.7 km day −1 . The SHKS group took daily 30 ml of water/kg body weight and 0.1 g of sodium chloride (NaCl)/kg body weight. Control subjects experienced no changes in their professional training and routine daily activities. Plasma volume (PV), urinary and plasma sodium (Na) and potassium (K), plasma osmolality, plasma protein, whole blood hemoglobin (Hb) and hematocrit (Hct), plasma renin activity (PRA) plasma aldosterone (PA) levels, physical characteristics, food and fluid intakes were measured. Plasma osmolality, plasma protein, urinary and plasma Na and K, whole blood Hct and Hb, PRA and PA levels decreased significantly ( p⩽0.01), while PV and body weight increased significantly ( p⩽0.01) in the SHKS group when compared with the UHKS group and did not change when compared with the UACS group. Plasma osmolality, plasma protein, urinary and plasma Na and K, PRA and PA, whole blood Hb and Hct levels increased significantly ( p⩽0.01), while PV body weight, food and fluid intakes decreased significantly ( p⩽0.01) in UHKS group when compared with the SHKS and UACS groups. The measured parameters did not change in the UACS group when compared with their baseline control values. It was shown that during HK body hydration decreased significantly, while during HK and FSS body hydration increased significantly. It was concluded that daily intake of FSS prevents the decrease of PV and blunts the increase of activity of the PRA and PA during prolonged HK.

Potassium supplements' effect on potassium balance in athletes during prolonged hypokinetic and ambulatory conditions.

Electrolyte supplements may be used to prevent changes in electrolyte balance during hypokinesia (diminished movement). The aim of this study was to measure the effect of potassium (K) supplements on K balance during prolonged hypokinesia (HK). Studies were done during 30 d of a pre-HK period and during 364 d of an HK period. Forty male athletes aged 25.1+/-4.4 yr were chosen as subjects. They were divided equally into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS) and supplemented ambulatory control subjects (SACS). The SHKS and UHKS groups were kept under an average walking distance of 0.7 km/d. The SACS and SHKS groups were supplemented daily with 50.0 mg elemental potassium chloride (KCl) per kilogram body weight. The K balance, fecal K excretion, urinary K, sodium (Na), and chloride (Cl) excretion, plasma K, Na, and Cl concentration, plasma renin activity (PRA) and plasma aldosterone (PA) concentration, anthropometric characteristics and peak oxygen uptake were measured. Negative K balance, fecal K excretion, urinary K, Na, and Cl excretion, plasma K, Na, and Cl concentration, and PRA and PA concentration increased significantly (p < or = 0.01), whereas body weight and peak oxygen uptake decreased significantly in the SHKS and UHKS groups when compared with SACS and UACS groups. However, the measured parameters changed much faster and much more in SHKS group than UHKS group. By contrast, K balance, fecal, urinary, and plasma K, plasma hormones, body weight, and peak oxygen uptake did not change significantly in the SACS and UACS groups when compared with the baseline control values. It was concluded that prolonged HK induces a significant negative K balance associated with increased plasma K concentration and urinary and fecal K excretion. However, negative K balance appeared much faster and was much greater in the SHKS group than UHKS group. Thus, K supplementation was not effective in preventing negative K balance during prolonged HK.

Daily copper supplement effects on copper balance in trained subjects during prolonged restriction of muscular activity

The aim of this study was to assess the effect of a daily intake of copper supplements on negative copper balance during prolonged exposure to hypokinesia (decreased number of kilometers per day). During hypokinesia (HK), negative copper balance is shown by increased, not by decreased, serum copper concentration, as it happens in other situations. Studies were done during a 30-d prehypokinetic period and a 364-d hypokinetic period. Forty male trained volunteers aged 22-26 yr with a peak oxygen uptake of 66.4 mL/min/kg and with an average of 13.7 km/d running distance were chosen as subjects. They were equally divided into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS), and supplemented ambulatory control subjects (SACS). The SACS and SHKS groups took 0.09 mg copper carbonate/kg body weight daily. The SHKS and UHKS groups were maintained under an average running distance of 1.7 km/d, whereas the SACS and UACS groups did not experience any modifications in their normal training routines. During the 30-d prehypokinetic period and the 346-d hypokinetic period, urinary excretion of copper, calcium, and magnesium and serum concentrations of copper, calcium, and magnesium were measured. Copper loss in feces and copper balance was also determined. In both UHKS and SHKS groups, urinary excretion of copper, calcium, and magnesium and concentrations of copper, magnesium, and calcium in serum increased significantly when compared with the SACS and UACS groups. Loss of copper in feces was also increased significantly in the SHKS and UHKS groups when compared with the UACS and SACS groups. Throughout the study, the copper balance was negative in the SHKS and UHKS groups, whereas in the SACS and UACS groups, the copper balance was positive. It was concluded that a daily intake of copper supplements cannot be used to prevent copper deficiency shown by increased copper concentration. Copper supplements also failed to prevent negative copper balance and copper losses in feces and urine in endurance-trained subjects during prolonged exposure to HK.

Magnesium Supplements’ Effect on Magnesium Balance in Athletes during Prolonged Restriction of Muscular Activity

Electrolyte supplements may be used to prevent negative electrolyte balance during hypokinesia (HK) (decreased number of kilometres per day). The aim of this study was to evaluate the effect of daily intakes of magnesium (Mg) supplements on Mg balance during prolonged HK. Studies were done during a 30–day period of pre–HK and during a 364–day period of HK. Forty male athletes aged 22–26 years were chosen as subjects. They were equally divided into four groups: unsupplemented ambulatory control (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS) and supplemented ambulatory control subjects (SACS). The SHKS and UHKS groups were maintained under an average running distance of 1.7 km/day, while the SACS and UACS groups experienced no changes in their professional training and routine daily activities. The SHKS and SACS groups took daily 23 mg Mg as Mg lactate per kilogram body weight. Mg balance, urinary and faecal Mg excretion and serum Mg concentration, anthropometric characteristics and peak oxygen uptake were measured. Negative Mg balance, faecal and urinary Mg excretion and serum Mg concentration increased significantly (p≤0.01) in the SHKS and UHKS groups when compared with the SACS and UACS groups. Serum, urinary and faecal Mg changes and negative Mg balance were much greater and appeared much faster in the SHKS group than in the UHKS group. Body weight and peak oxygen uptake decreased significantly (p≤0.01) in the SHKS and UHKS when compared with the SACS and UACS groups. By contrast, the corresponding parameters did not change significantly in the SACS and UACS groups when compared with the baseline control values. It was concluded that prolonged HK induces a significant negative Mg balance accompanied by significant Mg changes in urine, faeces and serum. Thus, using Mg supplements was not effective to prevent negative Mg balance in athletes during prolonged HK.

Daily hyperhydration effect on electrolyte deficiency of endurance-trained subjects during prolonged hypokinesia.

The aim of this study was to evaluate the effect of a daily intake of fluid and salt supplementation (FSS) on the deficiency of electrolytes, which is characterized by higher rather than lower plasma concentration of electrolytes during prolonged hypokinesia (HK) (decreased number of km taken per day). Forty long distance runners aged 22-25 yr with a peak VO2 65.4 mL min(-1) kg(-1) with an average 14.2 km d running distance were selected as subjects. They were equally divided into four groups: 1) unsupplemented control subjects (UCS); 2) unsupplemented hypokinetic subjects (UHS); 3) supplemented hypokinetic subjects (SHS), and 4) supplemented control subjects (SCS). During the investigation of 364 d, groups 2 and 3 maintained an average running distance of less than 4.7 km per day, groups 1 and 4 did not experience any modification in their normal training routines and diets. During the preexperimental period of 60 d and during the experimental period of 364 d urinary excretion of electrolytes and concentrations of sodium, potassium, calcium, and magnesium in plasma were determined. Whole blood hemoglobin, hematocrit index, plasma osmolality, and plasma protein concentration were measured. In the UHS plasma concentration of electrolytes and urinary excretion thereof, fluid elimination, hematocrit, whole blood hemoglobin, plasma osmolality, and plasma protein concentration increased significantly (p < 0.05) when compared with the UCS, SCS, and SHS groups. In the SHS plasma concentration of electrolytes and urinary excretion thereof, fluid excretion, whole blood hemoglobin, hematocrit, plasma osmolality, and plasma protein concentration decreased when compared with the UHS and increased insignificantly when compared with the UCS and SCS groups. It was concluded that FSS may be used to prevent or minimize electrolyte deficiency in endurance-trained volunteers during prolonged restriction of muscular activity.

Fluid-electrolyte changes in physically conditioned subjects after hypokinesia and chronic hyperhydration

The aim of this study was to determine whether fluid-electrolyte changes, which are developed during prolonged hypokinesia (decreased number of km per day), can be prevented or minimized with the use of a daily intake of fluid and salt supplementation (FSS). The experiments on hypokinesia (HK) were performed for 364 days on 18 endurance-trained male volunteers in the age range of 21–23 years, with an average maximum oxygen uptake of 67 ml kg −1. All volunteers were divided into three equal groups: six volunteers were placed on a continuous regime of exercise of 14.0 km day −1 and served as control subjects. Six volunteers were subjected to continuous HK without FSS and were considered as the unsupplemented hypokinetic subjects (UHS). The remaining volunteers were under continuous HK and FSS and were considered as the supplemented hypokinetic subjects (SHS). For the simulation of the hypokinetic effect, the UHS and SHS groups were kept continuously under an average of 2.7 km day −1 for the duration of the experiment. Prior to exposure to HK, all volunteers were on the same exercise regime as the controls. During the pre-experimental period of 60 days and during the post-experimental period, urinary excretion of electrolytes and concentrations of sodium, potassium, calcium and magnesium in serum as well as serum osmolality were determined. An increased renal excretion of fluid and electrolytes and a decreased serum electrolyte concentration were observed in the SHS, while a decreased renal excretion of fluid and electrolytes and an increased serum electrolyte concentration were observed in the UHS, during the initial stages of the post-hypokinetic period. By day 30 of the post-hypokinetic period these changes were reverted back to the control levels. We concluded that chronic hyperhydration may be used to attenuate urinary and serum electrolyte changes in endurance-trained volunteers after exposure to prolonged HK.